Display device

ABSTRACT

A display device includes a bottom chassis including first and second bottom portions, a mold frame including first and second frame portions disposed in respective first and second bottom portions, a hinge portion configured to couple the first and second frame portions to each other, a flexible display panel disposed on the mold frame and the hinge portion, a first curvature adjusting portion disposed between one side of the hinge portion and the display panel and coupled to the first frame portion, a second curvature adjusting portion disposed between the opposite side of the hinge portion and the display panel and coupled to the second frame portion, a first support portion coupled to the hinge portion and configured to support the first curvature adjusting portion, and a second support portion coupled to the hinge portion and configured to support the second curvature adjusting portion.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.14/806,899, filed on Jul. 23, 2015, and claims priority from and thebenefit of Korean Patent Application No. 10-2014-0126961, filed on Sep.23, 2014, which is hereby incorporated by reference for all purposes asif fully set forth herein.

BACKGROUND

Field

Exemplary embodiments of the invention relate to a display deviceincluding a flexible display panel, the display device configured toreduce excessive folding of a curved portion of a display panel.

Discussion of the Background

A foldable display device may include a flexible display panel that isbendable. The foldable display device may be portable and have a largescreen when unfolded, and to be used in various applications such as atelevision, a monitor, and a mobile device, e.g., mobile phone,ultra-mobile PC, e-books, and e-newspaper.

A high stress may be applied onto a curved portion of the foldedflexible display device. The high stress applied to the curved portionmay damage elements near the curved portion.

The above information disclosed in this Background section is only forenhancement of understanding of the background of the inventive concept,and, therefore, it may contain information that does not form the priorart that is already known in this country to a person of ordinary skillin the art.

SUMMARY

One or more exemplary embodiments provide a display device configured tostably control curvature of a curved portion of the display device so asto reduce or effectively prevent excessive folding of the curvedportion.

Additional aspects will be set forth in the detailed description whichfollows, and, in part, will be apparent from the disclosure, or may belearned by practice of the inventive concept.

According to one or more exemplary embodiments, a display deviceincludes: a bottom chassis including a first bottom portion and a secondbottom portion; a mold frame including a first frame portion and asecond frame portion respectively disposed in the first and secondbottom portions of the bottom chassis; a hinge portion configured tocouple the first and second frame portions of the mold frame to eachother; a flexible display panel disposed on the mold frame and the hingeportion; a first curvature adjusting portion disposed between one sideof the hinge portion and the flexible display panel, the first curvatureadjusting portion coupled to the first frame portion; a second curvatureadjusting portion disposed between the opposite side of the hingeportion and the display panel, the second curvature adjusting portioncoupled to the second frame portion; a first support portion coupled tothe hinge portion, the first support portion configured to support thefirst curvature adjusting portion; and a second support portion coupledto the hinge portion, the second support portion configured to supportthe second curvature adjusting portion.

Each of the first and second curvature adjusting portions comprises aplurality of adjustment units and a plurality of connecting shaftsconfigured to hinge couple the plurality of adjustment units to eachother.

At least two of the plurality of adjustment units have different angularrotation ranges.

An adjustment unit of the plurality of adjustment units that issubstantially closer to the hinge portion has a larger angular rotationrange.

At least one of the plurality of adjustment units have a upper surfaceand a lower surface having different lengths from each other.

An adjustment unit of the plurality of adjustment units disposedfurthest from the hinge portion comprises a surface that comprises aprojection and groove comprising a hole through which the connectingshaft is inserted.

Each adjustment unit of the plurality of adjustment units other than anadjustment unit of the plurality of adjustment units disposed furthestfrom the hinge portion comprise a surface comprising at least one firstprojection and at least one first groove having a first hole,alternately disposed, the connecting shaft is inserted through the firsthole of the first groove and an opposite surface comprising at least onesecond projection and at least one second groove having a second hole,alternately disposed, the connecting shaft is inserted through thesecond hole of the second groove.

The second groove is disposed corresponding to the first projection andthe second projection is disposed corresponding to the first groove.

The first and second grooves disposed closer from the hinge portion issmaller than the first and second grooves disposed further from thehinge portion.

Each of the plurality of adjustment units comprises a referenceadjustment unit, at least one curved adjustment unit between any one ofthe first and second frame portions and an end portion of the referenceadjustment unit and at least one straight adjustment unit hinge coupledto the opposite end portion of the reference adjustment unit.

The curved adjustment unit is configured to rotate in a range that doesnot intersect an imaginary reference surface extending from a surface ofthe reference adjustment unit; and wherein the straight adjustment unitis configured to rotate in a range that intersects (or crosses) theimaginary reference surface.

The hinge portion comprises: a shaft receiving portion and a hinge casecomprising a first gear receiving portion and a second gear receivingportion disposed respectively on two sides of the shaft receivingportion; a first hinge shaft and a second hinge shaft disposed in theshaft receiving portion; a first gear and a second gear disposed in thefirst gear receiving portion, the first and second gears are interlockedwith each other; a third gear and a fourth gear disposed in the secondgear receiving portion, the third and fourth gears are interlocked witheach other; a first gear cover covering a first opening formed in thefirst gear receiving portion, the first gear cover comprising throughholes through which axes of the first and second gears are respectivelydisposed and exposed outwards; a second gear cover covering a secondopening formed in the second gear receiving portion, the second gearcover comprising through holes through which axes of the third andfourth gears are respectively disposed and exposed outwards; a firstcoupling portion coupling the axis of the first gear to one side of thefirst frame portion; a second coupling portion coupling the axis of thethird gear to the opposite side of the first frame portion; a thirdcoupling portion coupling the axis of the second gear to one side of thesecond frame portion; and a fourth coupling portion coupling the axis ofthe fourth gear to the opposite side of the second frame portion.

The hinge portion further comprises a washer disposed on at least one ofpositions between one side of the first gear cover and the firstcoupling portion, between the opposite side of the first gear cove andthe third coupling portion, between one side of the second gear coverand the second coupling portion, and between the opposite side of thesecond gear cover and the fourth coupling portion.

The first gear receiving portion comprises through holes into which theaxes of the first and second gears are inserted; and wherein the secondgear receiving portion comprises through holes into which the axes ofthe third and fourth gears are inserted.

The shaft receiving portion comprises: first fixing grooves into whichtwo ends of the first hinge shaft are respectively inserted; secondfixing grooves into which two ends of the second hinge shaft arerespectively inserted; at least one first support groove configured tosupport a central portion of the first hinge shaft; and at least onesecond support groove configured to support a central portion of thesecond hinge shaft.

The first support portion is coupled to the first hinge shaft and thesecond support portion is coupled to the second hinge shaft.

The first support portion comprises: at least one rotation unitrotatably coupled to the first hinge axis; at least one first supportplate protruding from the rotation unit towards one side of the firstcurvature adjusting portion; and at least one second support plateprotruding from the rotation unit towards another side of the firstcurvature adjusting portion.

At least one hinge spring coupled to the first hinge axis, one end ofthe hinge spring disposed on the first support plate and the other endof the hinge spring disposed on the shaft receiving portion.

The second support portion comprises: at least one rotation unitrotatably coupled to the second hinge axis; at least one first supportplate protruding from the rotation unit towards one side of the secondcurvature adjusting portion; and at least one second support plateprotruding from the rotation unit towards another side of the secondcurvature adjusting portion.

At least one hinge spring coupled to the second hinge axis, one end ofthe hinge spring disposed on the first support plate and the other endof the hinge spring disposed on the shaft receiving portion.

The foregoing general description and the following detailed descriptionare exemplary and explanatory and are intended to provide furtherexplanation of the claimed subject matter.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the inventive concept, and are incorporated in andconstitute a part of this specification, illustrate exemplaryembodiments of the inventive concept, and, together with thedescription, serve to explain principles of the inventive concept.

FIG. 1 is a perspective view illustrating a display device according toone or more exemplary embodiments.

FIG. 2 is a perspective view illustrating a mold frame and a hingeportion illustrated in FIG. 1, disassembled from each other, accordingto one or more exemplary embodiments.

FIG. 3 is an exploded perspective view illustrating the hinge portionshown in FIG. 2, according to one or more exemplary embodiments.

FIG. 4 is a plan view and a front view illustrating the hinge portionshown in FIG. 2, according to one or more exemplary embodiments.

FIG. 5 is an exploded perspective view illustrating a first curvatureadjusting portion and first frame portion shown in FIG. 1, separatedfrom each other, according to one or more exemplary embodiments.

FIG. 6 is an exploded perspective view illustrating the first curvatureadjusting portion shown in FIG. 5 according to one or more exemplaryembodiments.

FIG. 7(a) is a plan view illustrating a structure of a first frameportion and a first curvature adjusting portion coupled to each otheraccording to one or more exemplary embodiments, and a FIGS. 7(b) and 7(c) are cross-sectional views respectively taken along sectional linesI-I′ and II-II′ of the structure of the first frame portion and thefirst curvature adjusting portion, according to one or more exemplaryembodiments.

FIG. 8 is a cross-sectional view of a first curvature adjusting portionand an enlarged view illustrating adjustment units, according to one ormore exemplary embodiments;

FIG. 9 is a cross-sectional view illustrating a first curvatureadjusting portion when curved, according to one or more exemplaryembodiments;

FIG. 10 is a perspective view illustrating an unfolded display deviceincluding a first curvature adjusting portion, a second curvatureadjusting portion, a first support portion and a second support portionaccording to on roe more exemplary embodiments.

FIG. 11 is a perspective view illustrating a folded display deviceincluding a first curvature adjusting portion, a second curvatureadjusting portion, a first support portion and a second support portionaccording to one or more exemplary embodiments.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

In the following description, for the purposes of explanation, numerousspecific details are set forth in order to provide a thoroughunderstanding of various exemplary embodiments. It is apparent, however,that various exemplary embodiments may be practiced without thesespecific details or with one or more equivalent arrangements. In otherinstances, well-known structures and devices are shown in block diagramform in order to avoid unnecessarily obscuring various exemplaryembodiments.

In the accompanying figures, the size and relative sizes of layers,films, panels, regions, etc., may be exaggerated for clarity anddescriptive purposes. Also, like reference numerals denote likeelements.

When an element or layer is referred to as being “on,” “connected to,”or “coupled to” another element or layer, it may be directly on,connected to, or coupled to the other element or layer or interveningelements or layers may be present. When, however, an element or layer isreferred to as being “directly on,” “directly connected to,” or“directly coupled to” another element or layer, there are no interveningelements or layers present. For the purposes of this disclosure, “atleast one of X, Y, and Z” and “at least one selected from the groupconsisting of X, Y, and Z” may be construed as X only, Y only, Z only,or any combination of two or more of X, Y, and Z, such as, for instance,XYZ, XYY, YZ, and ZZ. Like numbers refer to like elements throughout. Asused herein, the term “and/or” includes any and all combinations of oneor more of the associated listed items.

Although the terms first, second, etc. may be used herein to describevarious elements, components, regions, layers, and/or sections, theseelements, components, regions, layers, and/or sections should not belimited by these terms. These terms are used to distinguish one element,component, region, layer, and/or section from another element,component, region, layer, and/or section. Thus, a first element,component, region, layer, and/or section discussed below could be termeda second element, component, region, layer, and/or section withoutdeparting from the teachings of the present disclosure.

Spatially relative terms, such as “beneath,” “below,” “lower,” “above,”“upper,” and the like, may be used herein for descriptive purposes, and,thereby, to describe one element or feature's relationship to anotherelement(s) or feature(s) as illustrated in the drawings. Spatiallyrelative terms are intended to encompass different orientations of anapparatus in use, operation, and/or manufacture in addition to theorientation depicted in the drawings. For example, if the apparatus inthe drawings is turned over, elements described as “below” or “beneath”other elements or features would then be oriented “above” the otherelements or features. Thus, the exemplary term “below” can encompassboth an orientation of above and below. Furthermore, the apparatus maybe otherwise oriented (e.g., rotated 90 degrees or at otherorientations), and, as such, the spatially relative descriptors usedherein interpreted accordingly.

The terminology used herein is for the purpose of describing particularembodiments and is not intended to be limiting. As used herein, thesingular forms, “a,” “an,” and “the” are intended to include the pluralforms as well, unless the context clearly indicates otherwise. Moreover,the terms “comprises,” comprising,” “includes,” and/or “including,” whenused in this specification, specify the presence of stated features,integers, steps, operations, elements, components, and/or groupsthereof, but do not preclude the presence or addition of one or moreother features, integers, steps, operations, elements, components,and/or groups thereof.

Various exemplary embodiments are described herein with reference toplan and/or sectional illustrations that are schematic illustrations ofidealized exemplary embodiments and/or intermediate structures. As such,variations from the shapes of the illustrations as a result, forexample, of manufacturing techniques and/or tolerances, are to beexpected. Thus, exemplary embodiments disclosed herein should not beconstrued as limited to the particular illustrated shapes of regions,but are to include deviations in shapes that result from, for instance,manufacturing. For example, an implanted region illustrated as arectangle will, typically, have rounded or curved features and/or agradient of implant concentration at its edges rather than a binarychange from implanted to non-implanted region. Likewise, a buried regionformed by implantation may result in some implantation in the regionbetween the buried region and the surface through which the implantationtakes place. Thus, the regions illustrated in the drawings are schematicin nature and their shapes are not intended to illustrate the actualshape of a region of a device and are not intended to be limiting

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this disclosure is a part. Terms,such as those defined in commonly used dictionaries, should beinterpreted as having a meaning that is consistent with their meaning inthe context of the relevant art and will not be interpreted in anidealized or overly formal sense, unless expressly so defined herein.

FIG. 1 is a perspective view illustrating a display device according toone or more exemplary embodiments. FIG. 2 is a perspective viewillustrating a mold frame and a hinge portion shown in FIG. 1,disassembled from each other, according to one or more exemplaryembodiments.

Referring to FIGS. 1 and 2, a display device according to an exemplaryembodiment of the invention includes a bottom chassis 100, a mold frame200, a hinge portion 400, a support portion 500 (refer to FIG. 3), acurvature adjusting portion 600, a flexible display panel 700, and a topchassis 800.

The bottom chassis 100 may include a first bottom portion 100 a and asecond bottom portion 100 b. The first and second bottom portions 100 aand 100 b may be separated from each other. The first and second bottomportions 100 a and 100 b may be substantially symmetric to each otherwith respect to a Y-axis.

The first bottom portion 100 a may include a base portion 101 a and aplurality of side portions 102 a. The plurality of side portions 102 amay protrude from four respective edge portions of the base portion 101a by a predetermined height. Among the four side portions 102 a, a sideportion disposed corresponding to a center of the bottom chassis 100 mayhave the lowest height.

The lowest side portion 102 a disposed corresponding to a center of thebottom chassis 100 may be defined as a first side portion, and a sideportion disposed facing the first side portion may be defined as asecond side portion. The first bottom portion 100 a may be curved alonga direction from the first side portion towards the second side portion.

The base portion 101 a may have an inner surface including a firstsurface 1 a, a second surface 2 a, and a third surface 3 a, each havingheights different from each other. The first to third surfaces 1 a, 2 a,and 3 a may have a stair shape having gradually higher height from thefirst side portion to the second side portion. The first surface 1 a mayhave a height lower than the second surface 2 a, and the second surface2 a may have a height lower than the third surface 3 a.

The second bottom portion 100 b may include a base portion 101 b and aplurality of side portions 102 b, which is similar to the first bottomportion 100 a. The plurality of side portions 102 b may protrude fromfour respective edge portions of the base portion 101 b by apredetermined height. Among the four side portions 102 b, a side portiondisposed corresponding to a center of the bottom chassis 100 may havethe lowest height.

The lowest side portion 102 b disposed corresponding to a center of thebottom chassis 100 may be defined as a first side portion, and a sideportion disposed facing the first side portion may be defined as asecond side portion. The second bottom portion 100 b may be curved alonga direction from the first side portion towards the second side portion.

The base portion 101 b may have an inner surface including a firstsurface 1 b, a second surface 2 b, and a third surface 3 b, each havingheights different from each other. The first to third surfaces 1 b, 2 b,and 3 b may have a stair shape having gradually higher height from thefirst side portion to the second side portion. The first surface 1 b mayhave a height lower than the second surface 2 b, and the second surface2 b may have a height lower than the third surface 3 b.

The mold frame 200 may include a first frame portion 200 a and a secondframe portion 200 b. The first and second frame portions 200 a and 200 bmay be separated from each other. The first and second frame portions200 a and 200 b may be substantially symmetric to each other withrespect to the Y-axis.

The first frame portion 200 a may have a shape corresponding to thefirst bottom portion 100 a. That is, the first frame portion 200 a maybe curved along a direction from the first side portion of the firstbottom portion 100 a towards the second side portion thereof.

The first frame portion 200 a may include a first side wall 202 a 1 anda second sidewall 202 a 2 disposed facing each other, and a stage 201 adisposed between the first and second sidewalls 202 a 1 and 202 a 2. Thefirst and second sidewalls 202 a 1 and 202 a 2 may have a length longerthan the stage 201 a. In other words, portions of the first and secondsidewalls 202 a 1 and 202 a 2 may protrude over an edge portion of thestage 201 a towards the hinge portion 400. The portions of the first andsecond sidewalls 202 a 1 and 202 a 2 protruding over the edge portion ofthe stage 201 a may respectively be defined as first and second sidewallprotrusions 211 a 1 and 211 a 2.

The first sidewall 202 a 1 may have the same height as the secondsidewall 202 a 2. The first and second sidewalls 202 a 1 and 202 a 2 mayhave a height larger than the stage 201 a.

The first frame portion 200 a may be disposed corresponding to the firstbottom portion 100 a, which will be described below in more detail.

The first and second sidewalls 202 a 1 and 202 a 2 and the stage 201 a,which are included in the first frame portion 200 a, may be disposed onthe third surface 3 a of the first bottom portion 100 a. The firstsidewall protrusion 211 a 1 may be disposed on corresponding edgeportions of the first surface 1 a and the second surface 2 a. Therespective edge portions of the first and second surfaces 1 a and 2 amay have substantially the same height as the third surface 3 a. Thesecond sidewall protrusion 211 a 2 may be disposed on corresponding edgeportions of the first surface 1 a and the second surface 2 a. Therespective edge portions of the first and second surfaces 1 a and 2 amay have substantially the same height as the third surface 3 a.

The first frame portion 200 a may be affixed to the first bottom portion100 a using a coupling device such as a screw. Accordingly, the firstand second sidewalls 202 a 1 and 202 a 2 of the first frame portion 200a may include grooves disposed in the projections 27. The side portions102 a of the first bottom portion 100 a may include a plurality ofopenings (e.g., holes) 96 disposed corresponding to the plurality ofprojections 27. The coupling device may be coupled to the grooves in theplurality of projections 27 of the first frame portion 200 a through theplurality of openings (e.g., holes) 96 of the first bottom portion 100a.

The second frame portion 200 b may have a shape similar to the secondbottom portion 100 b. That is, the second frame portion 200 b may becurved along a direction from the first side portion of the secondbottom portion 100 b towards the second side portion thereof.

The second frame portion 200 b may include a first side wall 202 b 1 anda second sidewall 202 b 2 disposed facing each other, and a stage 201 bdisposed between the first and second sidewalls 202 b 1 and 202 b 2. Thefirst and second sidewalls 202 b 1 and 202 b 2 may have a length longerthan the stage 201 b. In other words, portions of the first and secondsidewalls 202 b 1 and 202 b 2 may protrude over an edge portion of thestage 201 b towards the hinge portion 400. The portions of the first andsecond sidewalls 202 b 1 and 202 b 2 protruding over the edge portion ofthe stage 201 a may respectively be defined as first and second sidewallprotrusions 211 b 1 and 211 b 2.

The first sidewall 202 b 1 may have the same height as the secondsidewall 202 b 2. The first and second sidewalls 202 b 1 and 202 b 2 mayhave a height larger than the stage 201 b.

The second frame portion 200 b may be disposed corresponding to thesecond bottom portion 100 b, which will be described below in moredetail.

The first and second sidewalls 202 b 1 and 202 b 2 and the stage 201 b,which are included in the second frame portion 200 b, may be disposed onthe third surface 3 b of the second bottom portion 100 b. The firstsidewall protrusion 211 b 1 may be disposed on corresponding edgeportions of the first surface 1 b and the second surface 2 b. Therespective edge portions of the first and second surfaces 1 b and 2 bmay have substantially the same height as the third surface 3 b. Thesecond sidewall protrusion 211 b 2 may be disposed on corresponding edgeportions of the first surface 1 b and the second surface 2 b. Therespective edge portions of the first and second surfaces 1 b and 2 bmay have substantially the same height as the third surface 3 b.

The second frame portion 200 b may be affixed to the second bottomportion 100 b using a coupling device such as a screw. Accordingly, thefirst and second sidewalls 202 b 1 and 202 b 2 of the second frameportion 200 b may include grooves disposed in the projections 27. Theside portions 102 b of the second bottom portion 100 b may include aplurality of openings (e.g., holes) 96 disposed corresponding to theplurality of projections 27. The coupling device may be coupled to thegrooves in the plurality of projections 27 of the second frame portion200 b through the plurality of openings (e.g., holes) 96 of the secondbottom portion 100 b.

Referring to FIGS. 1 and 2, the hinge portion 400 may be disposedbetween the first and second frame portions 200 a and 200 b.

The first frame portion 200 a may be rotatably coupled to one side ofthe hinge portion 400. The first frame portion 200 a may be coupled to afirst coupling portion 401 and a second coupling portion 402 of thehinge portion 400. For example, the first sidewall 202 a 1 may have agroove 20 in an outer side of the first sidewall 202 a 1 included in thefirst frame portion 200 a and the first coupling portion 401 may bepartially inserted into the groove 20. the second sidewall 202 a 2 mayhave a groove 20 in an outer side of the second sidewall 202 a 2included in the first frame portion 200 a and the second couplingportion 402 may be partially inserted into the groove 20.

The first and second coupling portions 401 and 402 may have a pluralityof coupling holes 25 that penetrate them, respectively. The first andsecond sidewalls 202 a 1 and 202 a 2 of the first frame portion 200 amay have a plurality of coupling grooves 24 respectively correspondingto the plurality of coupling holes 25. The coupling device, such as ascrew, may be inserted into the plurality of coupling grooves 24 throughthe coupling holes 25, and the first coupling portion 401 may be affixedto the first sidewall 202 a 1 of the first frame portion 200 a and thesecond coupling portion 402 may be affixed to the second sidewall 202 a2 of the first frame portion 200 a.

The second frame portion 200 b may be rotatably coupled to another sideof the hinge portion 400. The second frame portion 200 b may be coupledto a third coupling portion 403 and a fourth coupling portion 404 of thehinge portion 400. For example, the first sidewall 202 b 1 may have agroove 20 in an outer side of the first sidewall 202 b 1 included in thesecond frame portion 200 b and the third coupling portion 403 may bepartially inserted into the groove 20. the second sidewall 202 b 2 mayhave a groove 20 in an outer side of the second sidewall 202 b 2included in the second frame portion 200 b and the fourth couplingportion 404 may be partially inserted into the groove 20.

The third and fourth coupling portions 403 and 404 may have a pluralityof coupling holes 25 respectively that penetrate them, respectively. Thefirst and second sidewalls 202 b 1 and 202 b 2 of the second frameportion 200 b may have a plurality of coupling grooves 24 respectivelycorresponding to the plurality of coupling holes 25. The coupling devicesuch as a screw may be inserted into the plurality of coupling grooves24 through the coupling holes 25, and the third coupling portion 403 maybe affixed to the first sidewall 202 b 1 of the second frame portion 200b and the fourth coupling portion 404 may be affixed to the secondsidewall 202 b 2 of the second frame portion 200 b.

The hinge portion 400 will be further described with reference to FIG.3. FIG. 3 is an exploded perspective view illustrating the hinge portion400 shown in FIG. 2, according to one or more exemplary embodiments.FIG. 4 is a plan view and a front view illustrating the hinge portion400 shown in FIG. 2, according to one or more exemplary embodiments.

Referring to FIGS. 3 and 4, the hinge portion 400 may include a hingecase 499, a first hinge axis 471, a second hinge axis 472, a first gear851, a second gear 852, a third gear 853, a fourth gear 854, a firstgear cover 461, a second gear cover 462, a first washer 481, a secondwasher 482, a third washer 483, a fourth washer 484, a first couplingportion 401, a second coupling portion 402, a third coupling portion403, and a fourth coupling portion 404.

The hinge case 499 may include a shaft receiving portion 490 and firstand second gear receiving portions 411 and 412 respectively disposed ontwo opposite ends of the shaft receiving portion 490. The hinge case 499may include a translucent material such as plastic.

The shaft receiving portion 490 may include a bottom part 460 and afirst shaft fixing part 421, a plurality of first support parts 441,442, 431, 443, and 444, a plurality of first auxiliary support parts 451and 452, a second shaft fixing part 422, a third shaft fixing part 423disposed along another edge portion of the bottom part 460, a pluralityof second support parts 445, 446, 432, 447, and 448, a plurality ofsecond auxiliary support parts 453 and 454, and a fourth shaft fixingpart 424, disposed along edges of the bottom part 460.

The first and second shaft fixing parts 421 and 422 may be disposedfacing each other. An insertion groove 48 having a predetermined depthmay be defined in surfaces on the first and second shaft fixing parts421 and 422 respectively facing each other.

The plurality of first support parts 441, 442, 431, 443, and 444 mayinclude a first central support part 431 disposed on a middle betweenthe first and second shaft fixing parts 421 and 422, first and secondside support parts 441 and 442 disposed between the first centralsupport part 431 and the first shaft fixing part 421, and third andfourth side support parts 443 and 444 disposed between the first centralsupport part 431 and the second shaft fixing part 422.

The plurality of first auxiliary support parts 451 and 452 may include afirst auxiliary support part 451 disposed on one side of the firstcentral support part 431 and a second auxiliary support part 452disposed on the other side of the first central support part 431.

A support groove may be defined in respective inner sides of the firstcentral support part 431 and first, second, third, and fourth sidesupport parts 441, 442, 443, and 444. An auxiliary support groove may bedefined in respective inner sides of the first and second auxiliarysupport parts 451 and 452, which face the inner side of the firstcentral support part 431.

An end portion of the first hinge axis 471 may be inserted into theinsertion groove 48 of the first shaft fixing part 421, and the otherend portion of the first hinge axis 471 may be inserted into theinsertion groove 48 of the second shaft fixing part 422. A centralportion of the first hinge axis 471 may be supported by the supportgroove of the first central support part 431 and the auxiliary supportgrooves of the two auxiliary support parts 451 and 452. One side of thefirst hinge axis 471 may be supported by the support grooves of thefirst and second side support parts 441 and 442, and the other side ofthe first hinge axis 471 may be supported by the support grooves of thethird and fourth side support parts 443 and 444.

The first shaft fixing part 421, first and second side support parts 441and 442, first central support part 431, third and fourth side supportparts 443 and 444, and second shaft fixing part 422 may be spaced apartfrom each other, and may have an empty space therebetween. In moredetail, empty spaces may be respectively disposed between the firstshaft fixing part 421 and the first side support part 441, between thefirst and second side support parts 441 and 442, between the second sidesupport part 442 and the first central support part 431, between thefirst central support part 431 and the third side support part 443,between the third and fourth side support parts 443 and 444, and betweenthe fourth side support part 444 and the second shaft fixing part 422.

The third and fourth shaft fixing parts 423 and 424 may be disposedfacing each other. An insertion groove 48 having a predetermined depthmay be defined in surfaces on the third and fourth shaft fixing parts423 and 424 respectively facing each other.

The plurality of second support parts 445, 446, 432, 447, and 448 mayinclude a second central support part 432 disposed on a middle betweenthe third and fourth shaft fixing parts 423 and 424, fifth and sixthside support parts 445 and 446 disposed between the second centralsupport part 432 and the third shaft fixing part 423, and seventh andeighth side support parts 447 and 448 disposed between the secondcentral support part 432 and the fourth shaft fixing part 424.

A support groove may be defined in respective inner sides of the secondcentral support part 432 and fifth, sixth, seventh, and eighth sidesupport parts 445, 446, 447, and 448. An auxiliary support groove may bedefined in respective inner sides of the third and fourth auxiliarysupport parts 453 and 454, which face the inner side of the secondcentral support part 432.

An end portion of the second hinge axis 472 may be inserted into theinsertion groove 48 of the third shaft fixing part 423, and the otherend portion of the second hinge axis 472 may be inserted into theinsertion groove 48 of the fourth shaft fixing part 424. A centralportion of the second hinge axis 472 may be supported by the supportgroove of the second central support part 432 and the auxiliary supportgrooves of the two auxiliary support parts 453 and 454. One side of thesecond hinge axis 472 may be supported by the support grooves of thefifth and sixth side support parts 445 and 446, and the other side ofthe second hinge axis 472 may be supported by the support grooves of theseventh and eighth side support parts 447 and 448.

The third shaft fixing part 423, fifth and sixth side support parts 445and 446, second central support part 432, seventh and eighth sidesupport parts 447 and 448, and fourth shaft fixing part 424 may bespaced apart from each other, and may have an empty space therebetween.In more detail, empty spaces may be respectively disposed between thethird shaft fixing part 423 and the fifth side support part 445, betweenthe fifth and sixth side support parts 445 and 446, between the sixthside support part 446 and the second central support part 432, betweenthe second central support part 432 and the seventh side support part447, between the seventh and eighth side support parts 447 and 448, andbetween the eighth side support part 448 and the fourth shaft fixingpart 424.

The first gear receiving portion 411 may have a shape of a hollow case(or box). One side of the first gear receiving portion 411 may be open.The internal space of the first gear receiving portion 411 may beexposed outwards through the opening 430. Two first through holes 41 maybe defined in a surface of the first gear receiving portion 411 so as topenetrate the corresponding surface. The corresponding surface of thefirst gear receiving portion 411 may be disposed facing or opposing thesecond gear receiving portion 412.

The first gear cover 461 may be fitted into the opening 430 of the firstgear receiving portion 411 and cover the opening 430. The first gearcover 461 may have two second through holes 43 that penetrate the firstgear cover 461. The respective second through holes 43 may be formedcorresponding to the first through holes 41.

The first gear 851 may include a coupling portion including a pluralityof cogs and an axis shaft disposed in the center of the couplingportion. The coupling portion and axis shaft may be integrally formed.The plurality of cogs may be provided to a part of a circumference ofthe coupling portion.

The first gear 851 may be disposed within a space on one side of thefirst gear receiving portion 411. The first gear 851 may be fitted intothe corresponding first and second through holes 41 and 43. For example,one end of the axis shaft included in the first gear 851 may be insertedinto one of the first through holes 41 and the other end of the axisshaft of the first gear 851 may be inserted into one of the secondthrough holes 43 corresponding to the one first through hole 41. Theother end of the axis shaft may be exposed outwards through the secondthrough hole 43, and the exposed portion of the other end may have aquadrangle shape.

The second gear 852 may be disposed within a space on another side ofthe first gear receiving portion 411. The second gear 852 may include acoupling portion including a plurality of cogs and an axis shaftdisposed in the center of the coupling portion. The coupling portion andaxis shaft may be integrally formed. The plurality of cogs may beprovided to a part of a circumference of the coupling portion.

The second gear 852 may be fitted into the corresponding first andsecond through holes 41 and 43. For example, one end of the axis shaftincluded in the second gear 852 may be inserted into the other firstthrough hole 41 and the other end of the axis shaft of the second gear852 may be inserted into the other second through hole 43 correspondingto the other first through hole 41. The other end of the axis shaft maybe exposed outwards through the second through hole 43, and the exposedportion of the other end may have a quadrangle shape.

The first and second gears 851 and 852 may be coupled to each other. Theplurality of cogs of the first gear 851 may be interlocked with theplurality of cogs of the second gear 852.

The second gear receiving portion 412 may have a shape of a hollow case(or box). One side of the second gear receiving portion 412 may be open.The internal space of the second gear receiving portion 412 may beexposed outwards through the opening. Two first through holes 41 may bedefined in a surface of the second gear receiving portion 412 so as topenetrate the corresponding surface. The corresponding surface of thesecond gear receiving portion 412 may be disposed facing or opposing thefirst gear receiving portion 411.

The second gear cover 462 may be fitted into the opening of the secondgear receiving portion 412 and cover the opening. The second gear cover462 may have two second through holes 43 that penetrate the second gearcover 462. The respective second through holes 43 may be defined inplaces corresponding to the first through holes 41.

The third gear 853 may include a coupling portion including a pluralityof cogs and an axis shaft disposed in the center of the couplingportion. The coupling portion and axis shaft may be integrally formed.The plurality of cogs may be provided to a part of a circumference ofthe coupling portion.

The third gear 853 may be disposed within a space on one side of thesecond gear receiving portion 412. The third gear 853 may be fitted intothe corresponding first through holes 42 and second through holes. Forexample, one end of the axis shaft included in the third gear 853 may beinserted into one of the first through holes 42 and the other end of theaxis shaft of the third gear 853 may be inserted into one of the secondthrough holes corresponding to the one first through hole 42. The otherend of the axis shaft may be exposed outwards through the second throughhole, and the exposed portion of the other end may have a quadrangleshape.

The fourth gear 854 may be disposed within a space on another side ofthe second gear receiving portion 412. The fourth gear 854 may include acoupling portion including a plurality of cogs and an axis shaftdisposed in the center of the coupling portion. The coupling portion andaxis shaft may be integrally formed. The plurality of cogs may beprovided to a part of a circumference of the coupling portion.

The fourth gear 854 may be fitted into the corresponding first throughholes 42 and second through holes. For example, one end of the axisshaft included in the fourth gear 854 may be inserted into the otherfirst through hole 42 and the other end of the axis shaft of the fourthgear 854 may be inserted into the other second through holecorresponding to the other first through hole 42. The other end of theaxis shaft may be exposed outwards through the second through hole, andthe exposed portion of the other end may have a quadrangle shape.

The third and fourth gears 853 and 854 may be coupled to each other. Theplurality of cogs of the third gear 853 may be interlocked with theplurality of cogs of the fourth gear 854.

The first washer 481 may be disposed between the first gear cover 461and the first coupling portion 401. The first washer 481 may have a holethat penetrates a center thereof. The exposed portion of the axis shaftof the first gear 851 may be inserted through the hole of the firstwasher 481 and through a coupling hole 49 of the first coupling portion401. The other end of the axis shaft of the first gear 851 may be fittedinto the coupling hole 49 of the first coupling portion 401. The otherend portion of the axis shaft of the first gear 851 and the couplinghole 49 of the first coupling portion 401 may have a quadrangular shape,and therefore, a slippage between the first gear 851 and the firstcoupling portion 401 may be reduced.

The second washer 482 may be disposed between the first gear cover 461and the third coupling portion 403. The second washer 482 may have ahole that penetrates a center thereof. The exposed portion of the axisshaft of the second gear 852 may be inserted through the hole of thesecond washer 482 and through a coupling hole 49 of the third couplingportion 403. The other end of the axis shaft of the second gear 852 maybe fitted into the coupling hole 49 of the third coupling portion 403.The other end of the axis shaft of the second gear 852 and the couplinghole 49 of the third coupling portion 403 may have a quadrangular shape,and therefore, a slippage between the second gear 852 and the thirdcoupling portion 403 may be reduced.

The third washer 483 may be disposed between the second gear cover 462and the second coupling portion 402. The third washer 483 may have ahole that penetrates a center thereof. The exposed portion of the axisshaft of the third gear 853 may be inserted through the hole of thethird washer 483 and through a coupling hole of the second couplingportion 402. The other end of the axis shaft of the third gear 853 maybe fitted into the coupling hole of the second coupling portion 402. Theother end portion of the axis shaft of the third gear 853 and thecoupling hole of the second coupling portion 402 may have a quadrangularshape, and therefore, a slippage between the third gear 853 and thesecond coupling portion 402 may be reduced.

The fourth washer 484 may be disposed between the second gear cover 462and the fourth coupling portion 404. The fourth washer 484 may have ahole that penetrates a center thereof. The exposed portion of the axisshaft of the fourth gear 854 may be inserted through the hole of thefourth washer 484 and through a coupling hole of the fourth couplingportion 404. The other end of the axis shaft of the fourth gear 854 maybe fitted into the coupling hole of the fourth coupling portion 404. Theother end portion of the axis shaft of the fourth gear 854 and thecoupling hole of the fourth coupling portion 404 may have a quadrangularshape, and therefore, a slippage between the fourth gear 854 and thefourth coupling portion 404 may be reduced.

The first coupling portion 401 may have a shape of a long bar. One sideof the first coupling portion 401 may be rotatably coupled to the axisshaft of the first gear 851, and the other side of the first couplingportion 401 may be affixed to the first sidewall 202 a 1 of the firstframe portion 200 a. A coupling hole 49 may be defined in one side ofthe first coupling portion 401 so as to penetrate the first couplingportion 401 and a plurality of fastening holes 25 may be defined theother side of the first coupling portion 401 so as to penetrate thefirst coupling portion 401. The one side of the first coupling portion401 may have a smaller thickness than the other side thereof. Recessedgrooves 29 may be defined in two sides of a central portion of the firstcoupling portion 401. The projection 27 defined in the first sidewall202 a 1 of the first frame portion 200 a may be coupled with one grooveof the recessed grooves 29.

The second coupling portion 402 may have a shape of a long bar. One sideof the second coupling portion 402 may be rotatably coupled to the axisshaft of the second gear 852, and the other side of the second couplingportion 402 may be affixed to the second sidewall 202 a 2 of the firstframe portion 200 a. A coupling hole may be defined in one side of thesecond coupling portion 402 so as to penetrate the second couplingportion 402 and a plurality of fastening holes 25 may be defined in theother side of the second coupling portion 402 so as to penetrate thesecond coupling portion 402. The one side of the second coupling portion402 may have a smaller thickness than the other side thereof. Recessedgrooves may be defined in two sides of a central portion of the secondcoupling portion 402. The projection 27 defined in the second sidewall202 a 2 of the first frame portion 200 a may be coupled with one grooveof the recessed grooves.

The third coupling portion 403 may have a shape of a long bar. One sideof the third coupling portion 403 may be rotatably coupled to the axisshaft of the third gear 853, and the other side of the third couplingportion 403 may be affixed to the first sidewall 202 b 1 of the secondframe portion 200 b. A coupling hole may be defined in one side of thethird coupling portion 403 as to penetrate the third coupling portion403 and a plurality of fastening holes may be defined in the other sideof the third coupling portion 403 as to penetrate the third couplingportion 403. The one side of the third coupling portion 403 may have asmaller thickness than the other side thereof. Recessed grooves may bedefined in two sides of a central portion of the third coupling portion403. The projection defined in the first sidewall 202 b 1 of the secondframe portion 200 b may be coupled with one groove of the recessedgrooves.

The fourth coupling portion 404 may have a shape of a long bar. One sideof the fourth coupling portion 404 may be rotatably coupled to the axisshaft of the fourth gear 854, and the other side of the fourth couplingportion 404 may be affixed to the second sidewall 202 b 2 of the secondframe portion 200 b. A coupling hole may be defined in one side of thefourth coupling portion 404 as to penetrate the fourth coupling portion404 and a plurality of fastening holes may be defined in the other sideof the fourth coupling portion 404 as to penetrate the fourth couplingportion 404. The one side of the fourth coupling portion 404 may have asmaller thickness than the other side thereof. Recessed grooves may beformed in two sides of a central portion of the fourth coupling portion404. The projection defined in the second sidewall 202 b 2 of the secondframe portion 200 b may be coupled with one groove of the recessedgrooves.

The first to fourth coupling portions 401, 402, 403, and 404 mayrespectively have two recessed grooves 29, and thus the respective firstto fourth coupling portions 401, 402, 403, and 404 may be usedinterchangeably. For example, the first coupling portion 401 may be usedin place of the third coupling portion 403, and vice versa.

As illustrated in FIGS. 3 and 4, the support portion 500 may include afirst support portion 501 and a second support portion 502. The firstand second support portions 501 and 502 may be separated from eachother. Further, the first and second support portions 501 and 502 may besymmetric to each other with respect to the Y-axis.

The support portion 500 may include one or more first support portions501 and one or more second support portions 502. For example, accordingto FIG. 3, the support portion 500 includes two first support portions501 and two second support portions 502, but the exemplary embodimentsare not limited thereto.

The first support portion 501 may be rotatably coupled to the firsthinge axis 471. The first support portion 501 may include a firstrotation unit 511 a, a second rotation unit 512 a, a first support plate588 a, a second support plate 561 a, a third support plate 562 a, and ahinge spring 571 a. According to the exemplary embodiments, the firstsupport portion 501 may include one of either the first and secondrotation units 511 a and 512 a, and/or two or more of first and secondrotation units 511 a and 512 a. The first support portion 501 mayinclude two or more of first and second support plates 588 a and 561 a,and/or include two or more of the hinge spring.

The first rotation unit 511 a may have a shape of a cylinder. The firstrotation unit 511 a may have a through hole that penetrates a centralportion of the first rotation unit 511 a. The first rotation unit 511 amay be rotatably coupled to the first hinge axis 471 through the throughhole. The first rotation unit 511 a may be disposed in a space 45between the first shaft fixing part 421 and the first side support part441.

The second rotation unit 512 a may have a shape of a cylinder. Thesecond rotation unit 512 a may have a through hole that penetrates acentral portion of the second rotation unit 512 a. The second rotationunit 512 a may be rotatably coupled to the first hinge axis 471 throughthe through hole. The second rotation unit 512 a may be disposed in aspace 47 between the second side support part 442 and the first centralsupport part 431.

The first support plate 588 a may have a shape of a long bar. One sideof the first support plate 588 a may be coupled to one side of the firstrotation unit 511 a, and the other side of the first support plate 588 amay be coupled to one side of the second rotation unit 512 a. The firstsupport plate 588 a may protrude from the first and second rotationunits 511 a and 512 a towards one side of the first support portion 501.

The second support plate 561 a may have a shape of a bar shorter thanthe first support plate 588 a. The second support plate 561 a may becoupled to another side of the first rotation unit 511 a. The secondsupport plate 561 a may protrude from the first rotation unit 511 atowards another side of the first support portion 501. The secondsupport plate 561 a may have a smaller length and width than the firstsupport plate 588 a.

The third support plate 562 a may have a shape of a bar shorter than thefirst support plate 588 a. The third support plate 562 a may be coupledto another side of the second rotation unit 512 a. The third supportplate 562 a may protrude from the second rotation unit 512 a towardsanother side of the first support portion 501. The third support plate562 a may have a smaller length and width than the first support plate588 a. The third support plate 562 a may have the same size as thesecond support plate 561 a.

The first support plate 588 a may have an angle of greater than about 45degrees with the second support plate 561 a. For example, the firstsupport plate 588 a may have an angle of about 90 degrees with thesecond support plate 561 a.

The first support plate 588 a may have an angle of greater than about 45degrees with the third support plate 562 a. In an exemplary embodiment,for instance, the first support plate 588 a may have an angle of about90 degrees with the third support plate 562 a.

The hinge spring 571 a may be disposed in a space 46 between the firstand second side support parts 441 and 442. The hinge spring 571 a may becoiled around the first hinge axis 471. One end of the hinge spring 571a may extend straightly and may be disposed on the bottom part 460 ofthe hinge case 499, and the other end portion of the hinge spring 571 amay extend straightly and may be disposed on the first support plate 588a. An angle between the first support plate 588 a and the bottom part460 may be maintained constant by means of the hinge spring 571 a. Whena force greater than a restoring force of the hinge spring 571 a isapplied on the first support plate 588 a, the first support plate 588 amay press the other end portion of the hinge spring 571 a, andaccordingly an angle between the one end portion and the other endportion of the hinge spring 571 a may be reduced and energy may bestored in the hinge spring 571 a.

Referring to FIG. 3, another first support portion coupled to the firsthinge axis 471 may have the same shape as the above-described firstsupport portion 501. The another first support portion may include afirst rotation unit disposed in a space between the first centralsupport part 431 and the third side support part 443, a second rotationunit disposed in a space between the fourth side support part 444 andthe second shaft fixing part 422, and a hinge spring disposed in a spacebetween the third side support part 443 and the fourth side support part444.

The second support portion 502 may be rotatably coupled to the secondhinge axis 472. The second support portion 502 may include a firstrotation unit 511 b, a second rotation unit 512 b, a first support plate588 b, a second support plate 561 b, a third support plate 562 b, and ahinge spring 571 b. According to the exemplary embodiments, the secondsupport portion 502 may include one of either the first and secondrotation units 511 b and 512 b, and/or two or more of first and secondrotation units 511 b and 512 b. The second support portion 502 mayinclude two or more of first and second support plates 588 b and 561 b,and/or include two or more of the hinge spring.

The first rotation unit 511 b may have a shape of a cylinder. The firstrotation unit 511 b may have a through hole that penetrates a centralportion of the first rotation unit 511 b. The first rotation unit 511 bmay be rotatably coupled to the second hinge axis 472 through thethrough hole. The first rotation unit 511 b may be disposed in a spacebetween the third shaft fixing part 423 and the fifth side support part445.

The second rotation unit 512 b may have a shape of a cylinder. Thesecond rotation unit 512 b may have a through hole that penetrates acentral portion of the second rotation unit 512 b. The second rotationunit 512 b may be rotatably coupled to the second hinge axis 472 throughthe through hole. The second rotation unit 512 b may be disposed in aspace between the sixth side support part 446 and the second centralsupport part 432.

The first support plate 588 b may have a shape of a long bar. One sideof the first support plate 588 b may be coupled to one side of the firstrotation unit 511 b, and the other side of the first support plate 588 bmay be coupled to one side of the second rotation unit 512 b. The firstsupport plate 588 b may protrude from the first and second rotationunits 511 b and 512 b towards one side of the second support portion502.

The second support plate 561 b may have a shape of a bar shorter thanthe first support plate 588 b. The second support plate 561 b may becoupled to another side of the first rotation unit 511 b. The secondsupport plate 561 b may protrude from the first rotation unit 511 btowards another side of the second support portion 502. The secondsupport plate 561 b may have a smaller length and width than the firstsupport plate 588 b.

The third support plate 562 b may have a shape of a bar shorter than thefirst support plate 588 b. The third support plate 562 b may be coupledto another side of the second rotation unit 512 b. The third supportplate 562 b may protrude from the second rotation unit 512 b towardsanother side of the second support portion 502. The third support plate562 b may have a smaller length and width than the first support plate588 b. The third support plate 562 b may have the same size as thesecond support plate 561 b.

The first support plate 588 b may have an angle of greater than about 45degrees with the second support plate 561 b. For example, the firstsupport plate 588 b may have an angle of about 90 degrees with thesecond support plate 561 b.

The first support plate 588 b may have an angle of greater than about 45degrees with the third support plate 562 b. In an exemplary embodiment,for instance, the first support plate 588 b may have an angle of about90 degrees with the third support plate 562 b.

The hinge spring 571 b may be disposed in a space between the fifth andsixth side support parts 445 and 446. The hinge spring 571 b may becoiled around the second hinge axis 472. One end of the hinge spring 571b may extend straightly and may be disposed on the bottom part 460 ofthe hinge case 499, and the other end portion of the hinge spring 571 bmay extend straightly and may be disposed on the first support plate 588b. An angle between the first support plate 588 b and the bottom part460 may be maintained constant by means of the hinge spring 571 b. Whena force greater than a restoring force of the hinge spring 571 b isapplied on the first support plate 588 b, the first support plate 588 bmay press the other end portion of the hinge spring 571 b, andaccordingly an angle between the one end portion and the other endportion of the hinge spring 571 b may be reduced and energy may bestored in the hinge spring 571 b.

Referring to FIG. 3, another second support portion coupled to thesecond hinge axis 472 may have the same shape as the above-describedsecond support portion 502. The another second support portion mayinclude a first rotation unit disposed in a space between the secondcentral support part 432 and the seventh side support part 447, a secondrotation unit disposed in a space between the eighth side support part448 and the fourth shaft fixing part 424, and a hinge spring disposed ina space between the seventh side support part 447 and the eighth sidesupport part 448.

Referring back to FIG. 1, the curvature adjusting portion 600 mayinclude a first curvature adjusting portion 600 a and a second curvatureadjusting portion 600 b. The first and second curvature adjustingportions 600 a and 600 b may be separated from each other. Further, thefirst and second curvature adjusting portions 600 a and 600 b may bedisposed symmetric to each other with respect to the Y-axis.

The first curvature adjusting portion 600 a may be configured to controla curvature of a first curved part A1 of the flexible display panel 700.In other words, the first curvature adjusting portion 600 a may controla degree of curvature of the first curved part A1 so that the firstcurved part A1 may have a gentle (or low) curvature. The first curvedpart A1, as illustrated in FIG. 1, may be defined as a part of theflexible display panel 700, which is located between a center of theflexible display panel 700 and a first boundary portion. The firstboundary portion may be a boundary between the stage 201 a of the firstframe portion 200 a and the first curvature adjusting portion 600 a.

The first curvature adjusting portion 600 a may be disposed between oneside of the hinge portion 400 and the flexible display panel 700. Inmore detail, the first curvature adjusting portion 600 a may be disposedbetween the first support portion 501 coupled to the first hinge axis471 of the hinge portion 400 and the flexible display panel 700. Oneside of the first curvature adjusting portion 600 a may be disposedbetween the first and second sidewall protrusions 211 a 1 and 211 a 2 ofthe first frame portion 200 a. The first curvature adjusting portion 600a may be hinge coupled to the stage 201 a of the first frame portion 200a. A coupling structure of the first curvature adjusting portion 600 aand the first frame portion 200 a will be described below in moredetail.

FIG. 5 is an exploded perspective view illustrating the first curvatureadjusting portion 600 a and the first frame portion 200 a shown in FIG.1, separated from each other, according to one or more exemplaryembodiments.

Referring to FIG. 5, a plurality of projections 22 and a plurality ofgrooves 23 may be alternately disposed in a surface of the stage 201 aof the first frame portion 200 a facing the second frame portion 200 b.The respective projections 22 may have a shape of a hollow cylinder. Thefirst curvature adjusting portion 600 a may include a plurality ofprojections having shape of a hollow cylinder and a plurality ofgrooves, disposed in one side of first curvature adjusting portion 600a, facing the first frame portion 200 a. The plurality of projections 22of the stage 201 a of the first frame portion 200 a may be inserted intothe plurality of grooves of the first curvature adjusting portion 600 a,and the plurality of projections of the first curvature adjustingportion 600 a may be inserted into the plurality of grooves 23 of thestage 201 a of the first frame portion 200 a. The projections andgrooves of the stage 201 a of the first frame portion 200 a may becoupled to respective projections and grooves of the first curvatureadjusting portion 600 a, by inserting a connecting shaft 666 into holesof the coupled projections so that the first curvature adjusting portion600 a may be hinge coupled to the first frame portion 200 a. Theconnecting shaft 666 may be coupled to the stage 201 a of the firstframe portion 200 a through a through hole 66 that penetrates the secondsidewall protrusion 211 a 2.

FIG. 6 is an exploded perspective view illustrating the first curvatureadjusting portion 600 a shown in FIG. 5 according to one or moreexemplary embodiments. FIG. 7(a) is a plan view illustrating a structureof the first frame portion 200 a and the first curvature adjustingportion 600 a coupled to each other according to one or more exemplaryembodiments, and FIGS. 7(b) and 7 (c) are cross-sectional viewsrespectively taken along sectional lines I-I′ and II-II′ of thestructure of the first frame portion and the first curvature adjustingportion, according to one or more exemplary embodiments. That is, FIG.7(a) is a plan view, FIG. 7(b) is a cross-sectional view taken alongsectional line I-I′ of FIG. 7(a), and FIG. 7(c) is a cross-sectionalview taken along sectional line II-II′ of FIG. 7(a).

According to FIGS. 6, 7(a), 7(b), and 7(c), the first curvatureadjusting portion 600 a, may include a plurality of adjustment units601, 602, 603, 604, 605, and 606 and a plurality of connecting shafts667. The plurality of adjustment units 601, 602, 603, 604, 605, and 606may be hinge coupled to each other by the plurality of connecting shafts667. FIGS. 6, 7(a), 7(b), and 7(c) illustrates that the first curvatureadjusting portion 600 a includes six adjustment units 601, 602, 603,604, 605, and 606 hinge coupled to each other, but the exemplaryembodiments are not limited thereto. That is, the first curvatureadjusting portion 600 a may include a number of the adjustment unit(s)larger or smaller than the six units illustrated.

According to FIG. 6, the first to sixth adjustment units 601, 602, 603,604, 605, and 606 may have a shape of a bar having a length larger thana width. The first to sixth adjustment units 601, 602, 603, 604, 605,and 606 may all have the same width or at least two adjustment unitsthereof may have different widths from each other.

At least one first projection 61 and at least one first groove 62 may bealternately formed in one lateral surface of each of the first to fifthadjustment units 601, 602, 603, 604, and 605, and at least one secondprojection 63 and at least one second groove 64 may be alternatelyformed in another lateral surface of each of the first to fifthadjustment units 601, 602, 603, 604, and 605 opposite to the one lateralsurface thereof. The at least one second groove 64 may be formedcorresponding to the at least one first projection 61, and the at leastone second projection 63 may be defined corresponding to the at leastone first groove 62.

The at least one second projection 63 and the at least one second groove64 may be alternately defined in a surface of the sixth adjustment unit606 disposed closest to the hinge portion 400.

The at least one first and second projections 61 and 63 may have holesformed through central portions thereof, respectively.

The at least one first and second projections 61 and 63 may have aconvex shape, and the at least one first and second grooves 62 and 64may have a concave shape.

The first projection 61 formed on one of the adjustment units may bedisposed facing the second groove 64 respectively formed on adjacentadjustment units. The first projection 61 may be inserted into thefacing second groove 64. The projections 61 and 63 may be coupled torespective grooves 62 and 64 of the adjacent adjustment units, and theconnecting shaft 667 may be inserted into the holes of the projections61 and 63. In the way, the adjacent adjustment units may be hingecoupled to each other.

For example, the first projection 61 of the fourth adjustment unit 604may be inserted into the second groove 64 of the fifth adjustment unit605, and the second projection 63 of the fourth adjustment unit 604 maybe inserted into the first groove 62 of the third adjustment unit 603.Accordingly, the projections and grooves of the third to fifthadjustment units 603, 604, and 605 may be coupled to each other, and theconnecting shafts 667 may be inserted into the holes of the projections.

FIG. 8 is a cross-sectional view of the first curvature adjustingportion 600 a and an enlarged view illustrating adjustment unitsaccording to one or more exemplary embodiments.

At least two of the adjustment units included in the first curvatureadjusting portion 600 a may have different angular rotation ranges. Forexample, an adjustment unit disposed closer to the hinge portion 400 mayhave a larger angular rotation range. Referring to FIG. 8, the firstadjustment unit 601 disposed farthest from the hinge portion 400 mayhave the smallest angular rotation range (zero (0) degrees) and thesixth adjustment unit 606 disposed closest to the hinge portion 400 mayhave the largest angular rotation range (θ5). The second adjustment unit602 may have an angular rotation range (θ1) larger than the firstadjustment unit 601, the third adjustment unit 603 may have an angularrotation range (θ2) larger than the second adjustment unit 602, thefourth adjustment unit 604 may have an angular rotation range (θ3)larger than the third adjustment unit 603, the fifth adjustment unit 605may have an angular rotation range (θ4) larger than the fourthadjustment unit 604, and the sixth adjustment unit 606 may have anangular rotation range (θ5) larger than the fifth adjustment unit 605.The angular rotation range of the first adjustment unit 601 may besubstantially zero (0) degrees.

The grooves respectively included in the first to fifth adjustment units601, 602, 603, 604, and 605 that are closer to the hinge portion 400 maybe smaller. Referring to FIG. 8, the first adjustment unit 601 may havethe largest groove and the fifth adjustment unit 605 may have thesmallest groove. The second adjustment unit 602 may have a groovesmaller than the first adjustment unit 601, the third adjustment unit603 may have a groove smaller than the second adjustment unit 602, thefourth adjustment unit 604 may have a groove smaller than the thirdadjustment unit 603, the fifth adjustment unit 605 may have a groovesmaller than the fourth adjustment unit 604, and the sixth adjustmentunit 606 may have a groove smaller than the fifth adjustment unit 605.The sixth adjustment unit 606 may have a groove larger than the firstadjustment unit 601. In other words, the sixth adjustment unit 606 mayhave the largest groove among the first to sixth adjustment units 601,602, 603, 604, 605, and 606.

The respective first to sixth adjustment units 601, 602, 603, 604, 605,and 606 may include an upper surface 82 and a lower surface 81 which mayhave different size from each other. For example, the second adjustmentunit 602 may include the lower surface 81 that is smaller than the uppersurface 82 thereof. The sixth adjustment unit 606 may include the lowersurface 81 that is larger than the upper surface 82 thereof.

For example, the first adjustment unit 601 may include the upper andlower surfaces 82 and 81 having substantially identical size.

The upper surfaces 82 of the first to fourth adjustment units 601, 602,603, and 604 may be substantially same size.

The lower surfaces 81 respectively included in the first to fifthadjustment units 601, 602, 603, 604, and 605 which are closer to thehinge portion 400 may be smaller. Referring to FIG. 8, among the firstto fifth adjustment unit 601, 602, 603, 604, and 605, the firstadjustment unit 601 may include the largest lower surface 81 and thefifth adjustment unit 605 may include the smallest lower surface 81. Thesecond adjustment unit 602 may include the lower surface 81 smaller thanthe first adjustment unit 601, the third adjustment unit 603 may includethe lower surface 81 smaller than the second adjustment unit 602, thefourth adjustment unit 604 may include the lower surface 81 smaller thanthe third adjustment unit 603, the fifth adjustment unit 605 may includethe lower surface 81 smaller than the fourth adjustment unit 604, andthe sixth adjustment unit 606 may include the lower surface 81 smallerthan the fifth adjustment unit 605. The sixth adjustment unit 606 mayinclude the lower surface 81 that is larger than that of the firstadjustment unit 601. In other words, the sixth adjustment unit 606 mayinclude the largest lower surface 81 among the first to sixth adjustmentunits 601, 602, 603, 604, 605, and 606.

Respective distances between the connecting shafts 666 and 667 may besubstantially identical to each other. The respective distances betweenthe two connecting shafts 667 connecting two sides of the fifthadjustment unit 605 may be different from the distances between otherconnecting shafts. That is, the distances between the connecting shafts667 connecting the two sides of the fifth adjustment unit 605 may belarger than the distances between other connecting shafts since thefifth adjustment unit 605 includes a protrusion 615 protruding from oneside of the fifth adjustment unit 605 towards the sixth adjustment unit606.

One adjustment unit disposed between any two adjustment units of thefirst to sixth adjustment units 601, 602, 603, 604, 605, and 606 may bedefined as a reference adjustment unit. For example, the fifthadjustment unit 605 may be defined as the reference adjustment unit.Accordingly, the first to fourth adjustment units 601, 602, 603, and 604between the first frame portion 200 a and the reference adjustment unit605 (the fifth adjustment unit 605) may be defined as a curvedadjustment unit, and the sixth adjustment unit 606 between the referenceadjustment unit 605 (the fifth adjustment unit 605) and the hingeportion 400 may be defined as a straight adjustment unit. The curvedadjustment units 601, 602, 603, and 604 may be hinge coupled to eachother at one end portion of the reference adjustment unit 605, and thestraight adjustment unit 606 may be hinge coupled at the other endportion of the reference adjustment unit 605.

An imaginary surface extending from the upper surface 82 of thereference adjustment unit 605 may be defined as a reference surface 888,and the first to fourth curved adjustment units 601, 602, 603, and 604between the first frame portion 200 a and the reference adjustment unit605 may be rotated in a range that does not intersect (or cross) thereference surface 888, whereas the straight adjustment unit 606 betweenthe reference adjustment unit 605 and the hinge portion 400 may berotated in a range that the straight adjustment unit 606 intersects (orcrosses) the reference surface 888. This will be further described belowwith reference to FIG. 9. Hereinafter, the first to sixth adjustmentunits will be used in place of the reference adjustment unit, the firstto fourth curved adjustment units, and the straight adjustment unit.

FIG. 9 is a cross-sectional view illustrating the first curvatureadjusting portion 600 a when curved, according to one or more exemplaryembodiments.

As illustrated in FIG. 9, the first curvature adjusting portion 600 amay be curved along a curved surface of the flexible display panel 700,and then the first to sixth adjustment units 601, 602, 603, 604, 605,and 606 may be rotated along the curved surface. The upper surfaces 82of the respective first to fifth adjustment units 601, 602, 603, 604,and 605 do not intersect the reference surface 888, and the uppersurface 82 of the sixth adjustment unit 606 intersects the referencesurface 888.

The second curvature adjusting portion 600 b may be configured tocontrol a curvature of the second curved part A2 of the flexible displaypanel 700. In other words, the second curvature adjusting portion 600 bmay control a degree of curvature of the second curved part A2 that thesecond curved part A2 may have a gentle (or low) curvature. The secondcurved part A2, as illustrated in FIG. 1, may be defined as a part ofthe flexible display panel 700, which is located between a center of theflexible display panel 700 and a second boundary portion. The secondboundary portion may be a boundary between the stage 201 b of the secondframe portion 200 b and the second curvature adjusting portion 600 b.

The second curvature adjusting portion 600 b may be disposed between oneside of the hinge portion 400 and the flexible display panel 700. Inmore detail, the second curvature adjusting portion 600 b may bedisposed between the second support portion 502 coupled to the secondhinge axis 472 of the hinge portion 400 and the flexible display panel700. One side of the second curvature adjusting portion 600 b may bedisposed between the first and second sidewall protrusions 211 b 1 and211 b 2 of the second frame portion 200 b. The second curvatureadjusting portion 600 b may be hinge coupled to the stage 201 b of thesecond frame portion 200 b.

A detailed configuration of the second curvature adjusting portion 600 bmay be substantially same as the first curvature adjusting portion 600a, and thus, will be omitted.

Referring back to FIG. 1, the flexible display panel 700 may be disposedon the mold frame 200 and the curvature adjusting portion 600. One sideof the flexible display panel 700 may be placed on the stage 201 a ofthe first frame portion 200 a, and the other side of the flexibledisplay panel 700 may be placed on the stage 201 b of the second frameportion 200 b. The first curved part A1 of the flexible display panel700 may be located on the first curvature adjusting portion 600 a andthe second curved part A2 of the flexible display panel 700 may belocated on the second curvature adjusting portion 600 b.

The flexible display panel 700 may be substantially divided into twoareas; a display area 700 a and a non-display area 700 b. The displayarea 700 a may be configured to display an image and the non-displayarea 700 b may include signal lines configured to transmit image datafor image display, control signals and power signals. The non-displayarea 700 b may include a driver circuit board including at least onedriver circuit unit configure to provide the image data, control signalsand power signals.

The flexible display panel 700 may include a liquid crystal display(LCD) panel, an organic light emitting diode display (OLED) panel, aplasma display panel, an electrophoretic display panel, and the like,but exemplary embodiments are not limited thereto. The flexible displaypanel 700 may be any flexible display panel that is bendable andfoldable.

Referring back to FIG. 1, the top chassis 800 may have an openingthrough which the display area 700 a of the flexible display panel 700and a part of the hinge portion 400 are exposed. That is, the topchassis 800 may have a quadrangular frame shape including an opening inthe center of the top chassis 800. The top chassis 800 may include afirst top portion 800 a and a second top portion 800 b. The first andsecond top portions 800 a and 800 b may be separated from each other.The first and second top portions 800 a and 800 b may be symmetric toeach other with respect to the Y-axis.

The first top portion 800 a may be placed on the first and secondsidewalls 202 a 1 and 202 a 2 of the first frame portion 200 a and afirst side portion 900 a of a side case 900 that will be describedbelow. The first top portion 800 a may be affixed to the first andsecond sidewalls 202 a 1 and 202 a 2 and the first side portion 900 ausing a coupling device such as a screw.

The second top portion 800 b may be placed on the first and secondsidewalls 202 b 1 and 202 b 2 of the second frame portion 200 b and asecond side portion 900 b of the side case 900 that will be describedbelow. The second top portion 800 b may be affixed to the first andsecond sidewalls 202 b 1 and 202 b 2 and the second side portion 900 busing the coupling device such as a screw.

Referring back to FIG. 1, the side case 900 may include the first sideportion 900 a and the second side portion 900 b. The first and secondside portions 900 a and 900 b may be separated from each other. Thefirst and second side portions 900 a and 900 b may be symmetric to eachother with respect to the Y-axis.

The first side portion 900 a may be disposed on an edge portion of thefirst bottom portion 100 a. The first side portion 900 a may be attachedto a lower surface of the first top portion 800 a. The first sideportion 900 a may be affixed to the first top portion 800 a using thecoupling device.

The second side portion 900 b may be disposed on an edge portion of thesecond bottom portion 100 b. The second side portion 900 b may beattached to a lower surface of the second top portion 800 b. The secondside portion 900 b may be affixed to the second top portion 800 b usingthe coupling device.

FIG. 10 is a perspective view illustrating an unfolded display deviceincluding the first curvature adjusting portion 600 a, the secondcurvature adjusting portion 600 b, the first support portion 501 and thesecond support portion 502 according to one or more exemplaryembodiments.

According to FIG. 10, the unfolded display device may include theunfolded flexible display panel 700. The adjustment units 601, 602, 603,604, 605, and 606 of the first curvature adjusting portion 600 a and theadjustment units 601, 602, 603, 604, 605, and 606 of the secondcurvature adjusting portion 600 b may be aligned with respect to thereference surface 888.

Accordingly, the respective upper surfaces of the first to sixthadjustment units 601, 602, 603, 604, 605, and 606 of the first curvatureadjusting portion 600 a may be in contact with the flexible displaypanel 700, and the respective upper surfaces of the first to sixthadjustment units 601, 602, 603, 604, 605, and 606 of the secondcurvature adjusting portion 600 b may be in contact with the flexibledisplay panel 700.

The first support plate 588 a of the first support portion 501 may beconfigured to support one side of the sixth adjustment unit 606 includedin the first curvature adjusting portion 600 a, and the second and thirdsupport plates 561 a and 562 a of the first support portion 501 may beconfigured to support the other side of the sixth adjustment unit 606included in the first curvature adjusting portion 600 a.

The first support plate 588 b of the second support portion 502 may beconfigured to support one side of the sixth adjustment unit 606 includedin the second curvature adjusting portion 600 b, and the second andthird support plates 561 b and 562 b of the second support portion 502may be configured to support the other side of the sixth adjustment unit606 included in the second curvature adjusting portion 600 b.

FIG. 11 is a perspective view illustrating a folded display deviceincluding the first curvature adjusting portion 600 a, the secondcurvature adjusting portion 600 b, the first support portion 501 and thesecond support portion 502 according to one or more exemplaryembodiments.

According to FIG. 11, the folded display device may include the foldedflexible display panel 700. Since the flexible display panel 700 isfolded, the first curved part A1 may apply pressure on the firstcurvature adjusting portion 600 a. Accordingly, the first to sixthadjustment units 601, 602, 603, 604, 605, and 606 of the first curvatureadjusting portion 600 a may be moved towards the first bottom portion100 a rotated about the respective connecting shafts 667. Therefore, theupper surfaces 82 of the first to fifth adjustment units 601, 602, 603,604, and 605 of the first curvature adjusting portion 600 a may becurved. The coupling portion between the fifth and sixth adjustmentunits 605 and 606 of the first curvature adjusting portion 600 a may bedisposed on the second surface 2 a of the first bottom portion 100 a.The first support plate 588 a included in the first support portion 501may be rotated towards the first bottom portion 100 a, and one side ofthe first support plate 588 a may be disposed on the first surface 1 aof the first bottom portion 100 a by the rotation. One side of the sixthadjustment unit 606 of the first curvature adjusting portion 600 a maybe moved to a space between the first and second support plates 588 aand 561 a.

The first to sixth adjustment units 601, 602, 603, 604, 605, and 606 ofthe first curvature adjusting portion 600 a may have a limited angularrotation range, and thus a curvature of the first curved part A1 may belimited. An area B1 of the first curved part A1, which is near the firstboundary portion, may have a relatively high curvature according to thefirst curvature adjusting portion 600 a. The first curvature adjustingportion 600 a is configured to limit the curvature of the area B1 to apredetermined value and reduce or prevent excessive folding of the areaB1 of the first curved part A1 when the display device is folded.

Similarly, since the flexible display panel 700 is folded, the secondcurved part A2 may apply pressure on the second curvature adjustingportion 600 b. Accordingly, the first to sixth adjustment units 601,602, 603, 604, 605, and 606 of the second curvature adjusting portion600 b may be moved towards the second bottom portion 100 b rotated aboutthe respective connecting shafts 667. Therefore, the upper surfaces 82of the first to fifth adjustment units 601, 602, 603, 604, and 605 ofthe second curvature adjusting portion 600 b may be curved. The couplingportion between the fifth and sixth adjustment units 605 and 606 of thesecond curvature adjusting portion 600 b may be disposed on the secondsurface 2 b of the second bottom portion 100 b. The first support plate588 b included in the second support portion 502 may be rotated towardsthe second bottom portion 100 b, and one side of the first support plate588 b may be disposed on the first surface 1 b of the second bottomportion 100 b by the rotation. One side of the sixth adjustment unit 606of the second curvature adjusting portion 600 b may be moved to a spacebetween the first and second support plates 588 b and 561 b.

The first to sixth adjustment units 601, 602, 603, 604, 605, and 606 ofthe second curvature adjusting portion 600 b may have a limited angularrotation range, and thus a curvature of the second curved part A2 may belimited. An area B2 of the second curved part A2, which is near thesecond boundary portion, may have a relatively high curvature accordingto the second curvature adjusting portion 600 b. The second curvatureadjusting portion 600 b is configured to limit the curvature of the areaB2 to a predetermined value and reduce or prevent excessive folding ofthe area B2 of the second curved part A2 when the display device isfolded.

Although certain exemplary embodiments and implementations have beendescribed herein, other embodiments and modifications will be apparentfrom this description. Accordingly, the inventive concept is not limitedto such embodiments, but rather to the broader scope of the presentedclaims and various obvious modifications and equivalent arrangements.

What is claimed is:
 1. A display device comprising: a bottom chassiscomprising a first bottom portion and a second bottom portion; a moldframe comprising a first frame portion and a second frame portionrespectively disposed in the first and second bottom portions of thebottom chassis; a hinge portion configured to couple the first andsecond frame portions of the mold frame to each other; a flexibledisplay panel disposed on the mold frame and the hinge portion; a firstcurvature adjusting portion disposed between one side of the hingeportion and the flexible display panel, the first curvature adjustingportion coupled to the first frame portion; a second curvature adjustingportion disposed between the opposite side of the hinge portion and thedisplay panel, the second curvature adjusting portion coupled to thesecond frame portion; a first support portion coupled to the hingeportion, the first support portion configured to support the firstcurvature adjusting portion; and a second support portion coupled to thehinge portion, the second support portion configured to support thesecond curvature adjusting portion.
 2. The display device of claim 1,wherein each of the first and second curvature adjusting portionscomprises: a plurality of adjustment units; and a plurality ofconnecting shafts configured to hinge couple the plurality of adjustmentunits to each other.
 3. The display device of claim 2, wherein at leasttwo of the plurality of adjustment units have different angular rotationranges.
 4. The display device of claim 3, wherein an adjustment unit ofthe plurality of adjustment units that is substantially closer to thehinge portion has a larger angular rotation range.
 5. The display deviceof claim 2, wherein at least one of the plurality of adjustment unitshave a upper surface and a lower surface having different lengths fromeach other.
 6. The display device of claim 2, wherein an adjustment unitof the plurality of adjustment units disposed furthest from the hingeportion comprises a surface that comprises a projection and groovecomprising a hole through which the connecting shaft is inserted.
 7. Thedisplay device of claim 2, wherein each adjustment unit of the pluralityof adjustment units other than an adjustment unit of the plurality ofadjustment units disposed furthest from the hinge portion comprise: asurface comprising at least one first projection and at least one firstgroove having a first hole, alternately disposed, the connecting shaftis inserted through the first hole of the first groove; and an oppositesurface comprising at least one second projection and at least onesecond groove having a second hole, alternately disposed, the connectingshaft is inserted through the second hole of the second groove.
 8. Thedisplay device of claim 7, wherein the second groove is disposedcorresponding to the first projection and the second projection isdisposed corresponding to the first groove.
 9. The display device ofclaim 7, wherein the first and second grooves disposed closer from thehinge portion is smaller than the first and second grooves disposedfurther from the hinge portion.
 10. The display device of claim 2,wherein each of the plurality of adjustment units comprises: a referenceadjustment unit; at least one curved adjustment unit between any one ofthe first and second frame portions and an end portion of the referenceadjustment unit; and at least one straight adjustment unit hinge coupledto the opposite end portion of the reference adjustment unit.
 11. Thedisplay device of claim 10, wherein the curved adjustment unit isconfigured to rotate in a range that does not intersect an imaginaryreference surface extending from a surface of the reference adjustmentunit; and wherein the straight adjustment unit is configured to rotatein a range that intersects (or crosses) the imaginary reference surface.12. The display device of claim 1, wherein the hinge portion comprises:a shaft receiving portion and a hinge case comprising a first gearreceiving portion and a second gear receiving portion disposedrespectively on two sides of the shaft receiving portion; a first hingeshaft and a second hinge shaft disposed in the shaft receiving portion;a first gear and a second gear disposed in the first gear receivingportion, the first and second gears are interlocked with each other; athird gear and a fourth gear disposed in the second gear receivingportion, the third and fourth gears are interlocked with each other; afirst gear cover covering a first opening formed in the first gearreceiving portion, the first gear cover comprising through holes throughwhich axes of the first and second gears are respectively disposed andexposed outwards; a second gear cover covering a second opening formedin the second gear receiving portion, the second gear cover comprisingthrough holes through which axes of the third and fourth gears arerespectively disposed and exposed outwards; a first coupling portioncoupling the axis of the first gear to one side of the first frameportion; a second coupling portion coupling the axis of the third gearto the opposite side of the first frame portion; a third couplingportion coupling the axis of the second gear to one side of the secondframe portion; and a fourth coupling portion coupling the axis of thefourth gear to the opposite side of the second frame portion.
 13. Thedisplay device of claim 12, wherein the hinge portion further comprisesa washer disposed on at least one of positions between one side of thefirst gear cover and the first coupling portion, between the oppositeside of the first gear cover and the third coupling portion, between oneside of the second gear cover and the second coupling portion, andbetween the opposite side of the second gear cover and the fourthcoupling portion.
 14. The display device of claim 12, wherein the firstgear receiving portion comprises through holes into which the axes ofthe first and second gears are inserted; and wherein the second gearreceiving portion comprises through holes into which the axes of thethird and fourth gears are inserted.
 15. The display device of claim 12,wherein the shaft receiving portion comprises: first fixing grooves intowhich two ends of the first hinge shaft are respectively inserted;second fixing grooves into which two ends of the second hinge shaft arerespectively inserted; at least one first support groove configured tosupport a central portion of the first hinge shaft; and at least onesecond support groove configured to support a central portion of thesecond hinge shaft.
 16. The display device of claim 12, wherein thefirst support portion is coupled to the first hinge shaft and the secondsupport portion is coupled to the second hinge shaft.
 17. The displaydevice of claim 16, wherein the first support portion comprises: atleast one rotation unit rotatably coupled to a first hinge axis; atleast one first support plate protruding from the rotation unit towardsone side of the first curvature adjusting portion; and at least onesecond support plate protruding from the rotation unit towards anotherside of the first curvature adjusting portion.
 18. The display device ofclaim 17, further comprising at least one hinge spring coupled to thefirst hinge axis, one end of the hinge spring disposed on the firstsupport plate and the other end of the hinge spring disposed on theshaft receiving portion.
 19. The display device of claim 16, wherein thesecond support portion comprises: at least one rotation unit rotatablycoupled to a second hinge axis; at least one first support plateprotruding from the rotation unit towards one side of the secondcurvature adjusting portion; and at least one second support plateprotruding from the rotation unit towards another side of the secondcurvature adjusting portion.
 20. The display device of claim 19, furthercomprising at least one hinge spring coupled to the second hinge axis,one end of the hinge spring disposed on the first support plate and another end of the hinge spring disposed on the shaft receiving portion.